Dr Daniel Mansfield with the Plimpton 322 Babylonian clay tablet in the Rare Book and Manuscript Library at Columbia University in New York. Picture: UNSW/Andrew KellySource:Supplied

SCIENTISTS at a university in Sydney have solved a mystery that’s had mathematicians around the world scratching their heads for the better part of a century.

Since the discovery of the famous 3700-year old Babylonian clay tablet, known as Plimpton 322, in the early 1900s in southern Iraq, mystery has surrounded what the ‘triangular’ code was used for.

But University of New South Wales scientists have cracked the code, revealing it was possibly used by ancient mathematical scribes to calculate how to construct palaces and temples and build canals.

“Plimpton 322 has puzzled mathematicians for more than 70 years, since it was realised it contains a special pattern of numbers called Pythagorean triples,” Dr Daniel Mansfield of the School of Mathematics and Statistics in the UNSW Faculty of Science said in a statement.

“The tablet not only contains the world’s oldest trigonometric table; it is also the only completely accurate trigonometric table, because of the very different Babylonian approach to arithmetical and geometry.”

Dr Mansfield was looking for material to use in the classroom where he teaches mathematics when he came across prior research on the tablet “purely by chance,” he told news.com.au.

Like other mathematicians he recognised it as likely to be some sort of trigonometry but couldn’t figure out how. It was the help of a colleague down the hall that gave him an advantage over other researchers who had tried to understand the tablet.

“The thing that I had that was different was professor Norman Wildberger,” he said.

Prof Wildberger has previously done plenty of work on trigonometry based on ratios, rather than angles and circles like we currently understand — and that turned out to be the key to cracking the code.

“Once we looked at it in a different way, it all fell into place.” Dr Mansfield said.

After taking the ratio-centric approach, they then embarked on a long slog of reading nearly 70 years of research on the tablet and seeking to disprove previous theories and refine their own.

A a 3700 year old Babylonian tablet held in the Rare Book and Manuscript Library at Columbia University in New York.Source:Supplied

Its use of ratio-based trigonometry rather than trigonometry based on angles and circles makes it the world’s most accurate trigonometric table, according to Dr Mansfield.

“This provides a new way of looking at trigonometry,” he told news.com.au. “That’s the valuable part.”

It gives great insight the mathematical culture and history of the Babylonians. “People don’t tend to think of maths as having a large cultural aspect to it, but it does,” he said.

“It is a fascinating mathematical work that demonstrates undoubted genius.”

It also reveals the Babylonians, not the Greeks, were the first to study trigonometry — the study of triangles — and opens up new possibilities for modern mathematics research and education.

“With Plimpton 322 we see a simpler, more accurate trigonometry that has clear advantages over our own,” Prof Wildberger told AAP.

It took two years for Dr Mansfield and UNSW associate professor Norman Wildberger to come up with the theory, and now they’re calling on scientists to test it.

“I doubt we have nailed it, I want people to go out and test and criticise it and make it better through analysis and debate,” Dr Mansfield said last week.

The tablet has been dated to between 1822-1762 BC and sits in the Rare Book and Manuscript Library at Columbia University in New York.